Willy,

>The Entity object is empty (all nulls).

OK...the problem is that you are setting the entity object and then passing a DataSet to be saved which will subsequently overwrite whatever happened to be in the business object. Your easiest path here is to do this:

>protected void btnSave_Click(object sender, EventArgs e)
{
 DataSet dsFundingReports = (DataSet)Session["dsFundingReports"];
 this.oFundingReport.SetCurrentDataSet(dsFundingReports);

 //Modify the column Image Type
 oFundingReport.Entity.FundingReportImageType = "pdf";

 if (this.Save(this.oFundingReport) == mmSaveDataResult.RulesPassed) { }

}